Process cartridge and image forming apparatus including drum and shaft coupling members transmitting driving forces to a photosensitive drum and a developing roller, respectively

ABSTRACT

A process cartridge is detachably mountable to a main assembly of an electrophotographic image forming apparatus. The main assembly includes first and second rotatable main assembly drive transmission members. The cartridge includes an electrophotographic photosensitive drum, a developing roller, a drum coupling member, provided on one axial end of the drum, for engaging the first m transmission member and transmitting a first rotational driving force to the drum, when the cartridge is mounted to the main assembly, and a shaft coupler provided on one axial end of the developing roller, for transmitting a second rotational driving force with a deviation permitted between an axis of the second transmission member and an axis of the developing roller. The shaft coupler includes an engaging portion for engaging the second transmission member and receiving the second rotational driving force, when the cartridge is mounted to the main.

This application is a divisional of U.S. application Ser. No.11/869,344, filed Oct. 9, 2007, pending.

FIELD OF THE INVENTION AND RELATED ART Field of the Invention

The present invention relates to a process cartridge and anelectrophotographic image forming apparatus which uses the same.

Here, the electrophotographic image forming apparatus forms an image ona recording material using an electrophotographic type process. Examplesof the electrophotographic image forming apparatus include anelectrophotographic copying machine, an electrophotographic printer (forexample, a laser beam printer, LED printer, and so on), a facsimiledevice, and a word processor.

The process cartridge is a cartridge which comprises at least developingmeans and an electrophotographic photosensitive drum integrally formedin the cartridge, and it is detachably mountable to the main assembly ofthe electrophotographic image forming apparatus.

Heretofore, the photosensitive drum and the process means actable on thephotosensitive drum have been integrally unified into a cartridge in theelectrophotographic image forming apparatus using theelectrophotographic image forming process. A process-cartridge typeelectrophotographic image forming apparatus in which this cartridge isdetachably mountable to the main assembly of the electrophotographicimage forming apparatus, is employed. In this process-cartridge typeelectrophotographic image forming apparatus, the maintenance operationof the apparatus can be performed without depending on a service person,and therefore, the operability can be remarkably improved. Therefore,this process-cartridge type electrophotographic image forming apparatusis used widely.

Light corresponding to the image information, which can be generated by,for example, a laser, an LED, or a lamp, is projected onto thephotosensitive drum in the electrophotographic image forming apparatus.By doing so, an electrostatic latent image is formed on thephotosensitive drum. This electrostatic latent image is developed by adeveloping device. The developed image formed on the photosensitive drumis transferred onto a recording material. By doing so, the image isformed on the recording material.

JP 2001-255806A discloses a color electrophotographic image formingapparatus of the in-line type in which a plurality of process cartridgesare put in order by the one array. The process cartridge has a drum unitwhich includes a photosensitive drum, and a developing unit whichincludes a developing roller, and they are rotatably connected relativeto each other by a pin. The photosensitive drum is provided with acartridge coupling on an axial end of the photosensitive drum. When theprocess cartridge is mounted to the main assembly of the apparatus, acartridge coupling engages with a main assembly coupling provided in themain assembly of the apparatus, so that the driving force istransmitted. A driving force is transmitted to the developing rollerthrough the idler gears from the input gear as the development drivingforce transmission member provided on the pin of the developing unit.When the process cartridge is mounted to the main assembly of theapparatus The input gear is engaged with the gear provided in the mainassembly of the apparatus, and the engagement to receive the drivingforce. More particularly, the drive transmissions to the photosensitivedrum and to the developing roller from the main assembly of theapparatus are carried out independently from each other.

However, recently, further downsizing and image quality improvement ofthe process cartridge and the electrophotographic image formingapparatus are desired. The input gear is provided on the swing centerwhich does not change in the position even if the developing unit swingsin the conventional example. For this reason, the developing rollerrequires a space in order to receive the driving force from the inputgear through the idler gear of the process cartridge. The rotationalaccuracy of the developing roller is influenced by the engagement amongthe input gear, the idler gear, and the main assembly gear.

SUMMARY OF THE INVENTION

The present invention further develops the prior art structuresmentioned above.

Accordingly, it is a principal object of the present invention toprovide a process cartridge and a small size electrophotographic imageforming apparatus in which a rotational driving force is directlyinputted to the developing roller through the shaft coupling member fromthe main assembly of the apparatus independently from the driving inputto the photosensitive drum.

It is another object of the present invention to provide a processcartridge and an image forming apparatus in which the rotationalaccuracy of the developing roller is improved, so that the image qualityis improved.

According to another aspect of the present invention, there is provideda process cartridge detachably mountable to a main assembly of anelectrophotographic image forming apparatus. The main assembly includesa first rotatable main assembly drive transmission member, and a secondrotatable main assembly drive transmission member. The process cartridgecomprises an electrophotographic photosensitive drum; a developingroller for developing an electrostatic latent image formed on saidelectrophotographic photosensitive drum with a developer; a drumcoupling member, provided on one axial end of the electrophotographicphotosensitive drum, for engaging with the first main assembly drivetransmission member and transmitting a first rotational driving force tothe electrophotographic photosensitive drum, when the process cartridgeis mounted to the main assembly of the apparatus along an axialdirection of the electrophotographic photosensitive drum; a shaftcoupling member, provided on one axial end of the developing roller, fortransmitting a second rotational driving force with a deviationpermitted between an axis of the second main assembly drive transmissionmember and an axis of the developing roller. The shaft coupling memberincludes an engaging portion for engaging with the second main assemblydrive transmission member and receiving the second rotational drivingforce, when the process cartridge is mounted to the main assembly of theapparatus. The engaging portion is movable in a direction crossing withthe axial direction of the developing roller when the process cartridgeenters the main assembly of the apparatus.

According to another aspect of the present invention, there is providedan electrophotographic image forming apparatus for forming an image on arecording material, comprising: (i) a rotatable first main assemblydrive transmission member and a rotatable second main assembly drivetransmission member; and (ii) a process cartridge mounted detachably tothe main assembly of the apparatus of the electrophotographic imageforming apparatus. The process cartridge includes: anelectrophotographic photosensitive drum; a developing roller fordeveloping an electrostatic latent image formed on theelectrophotographic photosensitive drum with a developer; a drumcoupling member, provided on one axial end of the electrophotographicphotosensitive drum, for engaging with the first main assembly drivetransmission member and transmitting a first rotational driving force tothe electrophotographic photosensitive drum, when the process cartridgeis mounted to the main assembly of the apparatus along an axialdirection of the electrophotographic photosensitive drum; and a shaftcoupling member, provided on one axial end of the developing roller, fortransmitting a second rotational driving force with a deviationpermitted between an axis of the second main assembly drive transmissionmember and an axis of the developing roller. The shaft coupling memberincludes an engaging portion for engaging with the second main assemblydrive transmission member and receiving the second rotational drivingforce, when the process cartridge is mounted to the main assembly of theapparatus. The engaging portion is movable in a direction crossing withthe axial direction of the developing roller when the process cartridgeenters the main assembly of the apparatus. The apparatus also includes(iii) feeding means for feeding the recording material.

These and other objects, features, and advantages of the presentinvention will become more apparent upon consideration of the followingdescription of the preferred embodiments of the present invention, takenin conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a general arrangement of a color electrophotographic imageforming apparatus according to an embodiment 1 of the present invention.

FIG. 2 is a sectional view of a process cartridge according toEmbodiment 1.

FIG. 3 is the perspective view of an outer appearance of the processcartridge according to Embodiment 1.

FIG. 4 is a perspective view of a developing unit according toEmbodiment 1.

FIG. 5 illustrates a mounting operation relative to a main assembly ofthe image forming apparatus of the process cartridge according toEmbodiment 1.

FIG. 6 is a perspective view showing the state where the processcartridge according to Embodiment 1 is positioned in the main assemblyof the image forming apparatus.

FIG. 7 illustrates a supporting structure for a developing rolleraccording to Embodiment 1.

FIG. 8 is an exploded view of a shaft coupling member according toEmbodiment 1.

FIG. 9 is a sectional view of the shaft coupling member according toEmbodiment 1.

FIG. 10 is a perspective view of the shaft coupling member of adeveloping unit according to Embodiment 1.

FIG. 11 is a perspective view which illustrates a first main assemblydrive transmission member and a second main assembly drive transmissionmember of the image forming apparatus according to Embodiment 1.

FIG. 12 is a side view which illustrates an operation of the shaftcoupling member before the mounting of the process cartridge accordingto Embodiment 1.

FIG. 13 is a schematic illustration which illustrates the operation ofthe shaft coupling member before the mounting of the process cartridgeaccording to Embodiment 1.

FIG. 14 is a side view which illustrates the operation of the shaftcoupling member after the mounting of the process cartridge according toEmbodiment 1.

FIG. 15 is a schematic illustration which illustrates the operation ofthe shaft coupling member after the mounting of the process cartridgeaccording to Embodiment 1.

FIG. 16 is a side view which illustrates the positioning for the shaftcoupling member according to Embodiment 2.

FIG. 17 is a perspective view which illustrates the shaft couplingmember according to Embodiment 3.

FIG. 18 illustrates an operation of the shaft coupling member accordingto Embodiment 3.

FIG. 19 illustrates an operation of the shaft coupling member accordingto Embodiment 4.

FIG. 20 illustrates an operation of the shaft coupling member accordingto Embodiment 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiments of the present invention will be described inconjunction with the accompanying drawings.

Embodiment 1

Referring to FIG. 1-FIG. 15, the process cartridge and theelectrophotographic image forming apparatus according to an embodimentof the present invention will be described.

FIG. 1 illustrates a general arrangement of the colorelectrophotographic image forming apparatus according to thisembodiment.

(General Arrangement of Image Forming Apparatus)

FIG. 1 shows a general arrangement of an electrophotographic imageforming apparatus (hereinafter, image forming apparatus) 100. As shownin FIG. 1, four detachably mountable process cartridges 7 (7 a, 7 b, 7c, 7 d) are mounted by mounting members (unshown). In FIG. 1, theprocess cartridges 7 are inclined relative to the horizontal directionin the main assembly of the apparatus 100.

Each process cartridge 7 has an electrophotographic photosensitivemember drum (hereinafter, photosensitive drum) 1 (1 a, 1 b, 1 c, 1 d).Around the photosensitive drum 1 of the process cartridge 7, there areprovided process means, such as a charging roller 2 (2 a, 2 b, 2 c, 2d), a developing roller 25 (25 a, 25 b, 25 c, 25 d), and a cleaningmember 6 (6 a, 6 b, 6 c, 6 d), are provided integrally. The chargingroller 2 has a function of charging the surface of the photosensitivedrum 1 uniformly. The developing roller 25 has a function of developing,with the toner, a latent image formed on the photosensitive drum 1 intoa visualized image. The cleaning member 6 removes the toner whichremains on the photosensitive drum 1, after the developer image formedon the photosensitive drum 1 is transferred onto a recording material.

A scanner unit 3 for forming the latent image on the photosensitive drum1 by exposing the photosensitive drum 1 selectively on the basis of theimage information, is provided in a lower part of the process cartridge7.

A cassette 17, which contains the recording materials S, is provided ina lower position of the main assembly 100A of the apparatus. A recordingmaterial feeding means is provided so that the recording material Spasses through a secondary transfer roller 70 portion and a fixingportion 74 portion to the upper portion of apparatus main assembly A. Inthe detail, the recording material fixing means comprises a feedingroller 54 for carrying out the separation and feeding of the recordingmaterials S from the cassette 17 one by one. It further comprises aconveying roller pair 76 for feeding the fed recording material S, and aresist roller pair 55 for synchronizing the transfer of the latent imageformed on the photosensitive drum 1 with the movement of the recordingmaterial S. In an upper part of the process cartridge 7 (7 a, 7 b, 7 c,7 d), an intermediary transfer unit 5 as the intermediary transfer meansfor transferring the toner images formed on the photosensitive drums 1(1 a, 1 b, 1 c, 1 d), is provided. The intermediary transfer unit 5comprises a driving roller 56 and a follower roller 57. It furthercomprises primary transfer rollers (58 a, 58 b, 58 c, 58 d) provided inthe position opposed to the photosensitive drum 1 for each color, and anopposing roller 59 opposed to a secondary transfer rollers 70,respectively. A transfer belt 9 is extended around the rollers. Thecirculative movement of the transfer belt 9 is carried out so that thebelt 9 contacts all the photosensitive drums 1. By applying a voltage tothe primary transfer rollers (58 a, 58 b, 58 c, 58 d), the toner imagesare transferred primarily onto the transfer belt 9 from thephotosensitive drums 1. The voltage is applied between the opposingroller 59 disposed in the transfer belt 9, and the secondary transferrollers 70 to transfer the toner image from the transfer belt 9 onto therecording material S.

Each photosensitive drum 1 is rotated in the image forming operation andthe drum 1 is charged uniformly by the charging roller 2. Subsequently,the photosensitive drum 1 is selectively exposed to light with thescanner unit 3. By doing so, an electrostatic latent image is formed onthe photosensitive drum 1. The latent image is developed by thedeveloping roller 25. This forms the color developer image on eachphotosensitive drum 1. In synchronism with this image formation, aresist roller pair 55 feeds the recording material S to the secondarytransfer position where the opposing roller 59 and the secondarytransfer roller 70 are opposed to each other with the transfer belt 9therebetween. An image transfer bias voltage is applied to the secondarytransfer roller 70 to transfer the secondary color developer images onthe transfer belt onto the recording material S. By doing so, a colorimage is formed on the recording material S. The recording material Swhich has the formed color image is heated and pressed by the fixingportion 74, so that the developer image is fixed. Thereafter, therecording material S is discharged to the discharging portion 75 by thedischarging roller 72. The fixing portion 74 is disposed in the upperposition of main assembly 100A of the apparatus 100.

(Process Cartridge)

Referring to FIG. 2-FIG. 4, the process cartridge 7 of this embodimentwill be described. FIG. 2 is a major section of the process cartridge 7which contains the developer (hereinafter, toner). A cartridge 7 a whichcontains the toner of the yellow color, a cartridge 7 b which containsthe toner of a magenta color, a cartridge 7 c which contains the tonerof the cyan color, and a cartridge 7 d which contains the toner of theblack color, have the same structures.

Each process cartridge 7 (7 a, 7 b, 7 c, 7 d) includes a drum unit 26 asa first frame, and a developing unit 4 (4 a, 4 b, 4 c, 4 d) as a secondframe. The drum unit 26 is provided with the photosensitive drum 1 (1 a,1 b, 1 c, 1 d), and the charging roller 2 (2 a, 2 b, 2 c, 2 d) and thecleaning member 6 (6 a, 6 b, 6 c, 6 d). And, the developing unit 4 isprovided with a developing roller 25.

The drum unit 26 includes a cleaning frame 27 and the photosensitivedrum 1 is rotatably mounted to it through a drum-front bearing 10 and adrum-rear bearing 11 (FIG. 3). The end of the photosensitive drum 1 isprovided with the drum coupling 16 and the flange 85.

Around the photosensitive drum 1, as mentioned above, the chargingroller 2 and the cleaning member 6 are disposed. The residual tonerremoved by the cleaning member 6 from the photosensitive drum 1 surfaceis allowed to fall in a removed toner chamber 27 a. A driving force istransmitted to the drum unit 26 from a main assembly driving motor(unshown) as a driving source, so that the photosensitive drum 1 isrotated correspondingly to the image forming operation process. Thecharging roller 2 is rotatably mounted to the cleaning frame 27 throughthe charging roller bearings 28. And, it is pressed by a charging rollerpressing member 46 toward the photosensitive drum 1, by which it isrotated by the photosensitive drum 1.

The developing unit 4 comprises a developing roller 25 which contactsthe photosensitive drum 1 and is rotated in the direction of arrow B,and a developing device frame 31 for supporting the developing roller25. The developing roller 25 is rotatably supported on the developingdevice frame 31 through a developing-device-front bearing 12 and adeveloping-device-rear bearing 13 which are mounted to the respectivesides of the developing device frame 31 (FIG. 4). A toner supplyingroller 34 rotates in the direction of arrow C, contacting to the outerperiphery of the developing roller 25. A developing blade 35 regulatesthe toner layer thereon, contacting the outer periphery of thedeveloping roller 25. In the toner accommodating portion 31 a of thedeveloping device frame 31, the toner feeding member 36 for agitatingthe contained toner and for feeding the toner to the toner supplyingroller 34 is provided.

FIG. 3 is an outer appearance perspective view of the process cartridge7. The developing unit 4 is rotatably mounted to the drum unit 26. Afront supporting pin 14 and a rear supporting pin 15, which arepress-fitted in the cleaning frame 27. are engaged into the hangingholes 12 a and 13 a of the developing-device-front bearing 12 and thedeveloping-device-rear bearing 13. By doing so, the developing unit 4 isrotatably supported about the axis of the supporting pins 14 and 15 tothe cleaning frame 27 (FIG. 2). The cleaning frame 27 is provided with adrum-front bearing 10 and a drum-rear bearing 11 for supporting thephotosensitive drum 1 rotatably. The drum-rear bearing 11 supports adrum coupling 16 connected with the photosensitive drum 1. Thedrum-front bearing 10 supports the flange 85. The drum coupling 16transmits the rotational driving force (first rotational driving force)to the photosensitive drum 1 from the main assembly 100A of theapparatus 100.

The developing unit 4 shown in FIG. 4 is urged to the drum unit 26 by apressing spring 38 provided in the developing device frame 31, and atension spring (unshown) provided in the developing-device-front bearing12 during the image formation of the process cartridge 7. The developingroller 25 is revolved by the pressing springs 38 and the tension spring39 about the holes 12 a and 13 a of the developing-device-front bearing12 and the developing-device-rear bearing 13, so that it is contacted tothe photosensitive drum 1.

In a contact type developing system which effects the development withthe contact between the photosensitive drum 1 and the developing roller25, it is desirable that the photosensitive drum 1 is a rigid member andthe developing roller 25 is an elastic member. This elastic member maybe a solid rubber monolayer, and it may have a solid rubber layer and aresin material coating thereon in consideration of the chargingapplication property to the toner.

The image forming operation of the process cartridge 7 will be described(FIG. 1 and FIG. 2). When the image information is supplied to the imageforming apparatus 100, the main assembly driving motor (unshown) startsits rotation and the rotational driving forces are transmitted to thephotosensitive drum 1, to the developing roller 25, to the tonersupplying roller 34, and to the toner feeding member 36. The chargingbias voltage is applied to the charging roller 2 from the main assembly100A of the apparatus 100 to charge electrically the surface of thephotosensitive drum 1 uniformly. Corresponding to the image information,exposure is effected by the scanner unit 3, so that a latent image isformed on the photosensitive drum 1.

The toner in the toner accommodating portion 31 a is fed by the rotationof the toner feeding member 36 to the toner supplying roller 34. Thetoner supplying roller 34 rotates to supply the toner to the outerperiphery of the rotating developing roller 25. The supplied toner istriboelectrically charged by the developing blade 35 on the outerperiphery of the developing roller 25. The developing bias voltage isapplied to the developing roller 25 from the voltage source portion(unshown) provided in the image forming apparatus 100. By doing so, theelectrostatic latent image formed on the photosensitive drum 1 isdeveloped. Here, the developing roller 25 is provided opposed to thephotosensitive drum 1. The developing roller 25 is contacted to thephotosensitive drum 1 and develops the electrostatic latent image formedon the photosensitive drum 1.

(Mechanism for Mounting Process Cartridge to Main Assembly of ImageForming Apparatus)

Referring to FIG. 5, the mounting mechanism, according to thisembodiment, for mounting the process cartridge 7 in the apparatus mainassembly 100A will be described.

In FIG. 5, (a) illustrates a state before the setting, in the apparatusmain assembly 100A, of the process cartridge 7. In the state shown in(a), the process cartridge 7 is mounted in the direction of arrow Ethrough an opening 82 a provided in a front side plate 82 of theapparatus main assembly 100A. In that case, a guide portion 27 bintegrally provided in the cleaning frame 27 of the process cartridge 7is guided on a main assembly guide member 81 provided in the mainassembly 100A of the apparatus. The main assembly guide member 81 is themounting member for mounting the process cartridge 7 dismountably.

In FIG. 5, (b) illustrates the state where the mounting of the processcartridge 7 to the apparatus main assembly 100A is starting to be, butnot yet completed. The guiding member 81 provided in the main assembly100A of the apparatus is provided with an inclined portion 81 a inclinedupwardly toward the downstream direction with respect to the mountingdirection. The cleaning frame 27 is provided with a downwardly inclinedportion 27 c at an upstream end with respect to the mounting direction.When the process cartridge 7 is mounted to the apparatus main assembly100A, the guide portion 27 b of the cleaning frame 27 rides on theinclined portion 81 a, and the inclined portion 27 c rides on the mainassembly guide portion 81. By doing so, the process cartridge 7 isdisplaced toward the intermediary transfer unit 5 (upwardly).

In FIG. 5, (c) illustrates the state where the process cartridge ismounted to the main assembly 100A of the apparatus 100. When themounting operation of the process cartridge 7 is further continued afterthe process cartridge 7 moves toward the intermediary transfer unit 5,the abutting portion 27 d provided integrally on the cleaning frame 27contacts to a rear side plate 83 of the apparatus main assembly 100A. Bydoing so, the mounting of the process cartridge 7 to the image formingapparatus 100 is completed.

In this state, a portion-to-be-urged 11 a of the drum-rear bearing 11contacts the back pressed member 91 provided in the rear side plate 83,so that it is upwardly pushed by the pressing spring 92. And, thecartridge positioning portion 11 b provided in the upper position of thedrum-rear bearing 11 contacts the abutting portion 83 a, which functionsas the main assembly positioning portion, of the rear side plate 83, bywhich the process cartridge 7 is positioned relative to the apparatusmain assembly 100A in the rear side.

In addition, a portion-to-be-pulled 10 a of the drum-front bearing 10engages with the pulling member 93 provided in a front side plate 82.The pulling member 93 is upwardly raised by a tension spring 94 providedon the front side plate 82, and by doing so, the portion-to-be-pulled 10a is also upwardly raised. And, an abutting portion 10 b which iscartridge positioning portion for the drum-front bearing 10 contacts apositioning portion 82 b which is the main assembly positioning portionof the main assembly front side plate 82, so that the process cartridge7 is positioned relative to the apparatus main assembly 100A in thefront side.

As shown in FIG. 6, the abutting portion 83 a substantially has a Vconfiguration, and contacts the positioning surface 11 b of thedrum-rear bearing 11. The drum-front bearing 10 is pulled in thedirection of Arrow P by the locking with the portion-to-be-pulled 10 aof the drum-front bearing 10 of the pulling member 93 provided in thefront side plate 82. Relating to positioning, it is contacted to thedrum positioning portion 82 b which is provided in the front side plate82 and which has a substantially V configuration, similar to the case ofthe drum-rear bearing 11. The pressure required for the positioning,relative to the main assembly 100A of the apparatus 100, of thedrum-front bearing 10 and the drum-rear bearing 11, is applied in thedirection of Arrows P and R. Therefore, the process cartridge 7 ispositioned, namely, the drum-front bearing 10 and the drum-rear bearing11, which support the photosensitive drum 1 rotatably, can be correctlypositioned relative to the main assembly 100A of the apparatus 100. Inaddition, the cleaning frame 27 is provided with a boss 27 g whichfunctions as a rotation stopper for the process cartridge 7 on the sidesurface, and the boss 27 g engages with the rotation stopper receptormember 51 provided in the apparatus main assembly 100A. By doing so, therotation in the apparatus main assembly 100A of the process cartridge 7is prevented. For easy understanding of the description, the drivingside engaging portion 23 is omitted in FIG. 6.

(Structures of Developing Roller Supporting Portion and Developing DriveForce Input Portion in Process Cartridge)

Referring to FIG. 7-FIG. 11 a description will be provided about thesupporting structure for the structure of the developing drive forceinput portion, and the developing roller 25 in the process cartridge 7of this embodiment. FIG. 7 illustrates one longitudinal end side (rearside) of the supporting portion of the developing roller 25. In FIG. 7,the developing roller shaft 25 j of the developing roller 25 isrotatably engaged with the inner surface of the developing-device-rearbearing 13. Between the rubber roller portion 25 g of the developingroller 25 and the developing-device-rear bearing 13, a regulation roller47 for regulating the degree of contact, to the photosensitive drum 1,of the developing roller 25 engages with the developing roller shaft 25j rotatably. Heretofore, the supporting structure by the side of the onelongitudinal end of the developing roller 25 is described, but thebearing portion is similarly provided to the bearing member integrallyat the other end side in the longitudinal direction to support the otherend side of the developing roller shaft 25 j rotatably.

In this embodiment, an Oldham coupling 20, which is a shaft couplingmember. is used as the developing drive force input portion. Referringto FIG. 8 and FIG. 9, the structure of the Oldham coupling 20 will bedescribed. For easy understanding of the Oldham coupling 20, thedeveloping-device-rear bearing 13 is omitted, here.

As shown in FIG. 8, the Oldham coupling 20 comprises a driven sideengaging portion 21, an intermediary engaging portion 22, and a drivingside engaging portion 23.

The driven side engaging portion 21 is fixed to the end of thedeveloping roller shaft 25 j. As for the fixing method, the spring pinand the parallel pin can be used. In addition, as shown in FIG. 8, in analternative structure, the cut portion 25 c is provided on a peripheralsurface of the developing roller shaft 25 j, and a hole provided in thedriven side engaging portion 21 is provided with the complementaryconfiguration. A shaft portion 23 b of the driving side engaging portion23 is rotatably retained in the hole 19 a of an engaging portion bearingmember 19. The driving side engaging portion 23 is provided integrallywith the projections 23 c 1 to 23 c 4 and is engageable with a mainassembly development coupling 53 (FIG. 11), which is a second mainassembly drive transmission member of the main assembly 100A of theapparatus 100, as will be described hereinafter. This Oldham coupling 20transmits the rotational driving force (second rotational driving force)from the main assembly 100A of the apparatus 100 to the developingroller 25, permitting the deviation between the axis of the mainassembly development coupling 53 and the axis of the developing roller25.

Referring to sectional view of FIG. 9, the Oldham coupling 20 will bedescribed in more detail. FIG. 9 (a) is the sectional view taken alongthe surface perpendicular to the direction of arrow H of FIG. 8 and FIG.9 (b) is the sectional view taken along the surface perpendicular to thedirection of arrow I in FIG. 8.

The driven side engaging portion 21 is provided integrally with a rib 21a as shown in FIG. 9 (a). A groove 22 a is formed on the intermediaryengaging portion 22, and the rib 21 a and the groove 22 a are engagedwith each other in FIG. 8 for movement in the direction of arrow H.

The driving side engaging portion 23 is provided integrally with a rib23 a as shown in FIG. 9 (b). A groove 22 b is formed in the intermediaryengaging portion 22, and the rib 23 a and the groove 22 b are engagedwith each other for the movement in the direction of arrow I in FIG. 8.

FIG. 10 illustrates the structure of the coupling provided in theprocess cartridge 7. The projections 23 c 1-23 c 3 projected toward theaxial direction are formed in the end surface of the driving sideengaging portion 23 of the Oldham coupling 20 mounted to the developingunit 4. A centering boss 23 c 4 for alignment (rotation axis) relativeto the main assembly development coupling 53 projects in the directionof the axis from the end surface of the driving side engaging portion23. The one end side of the axial direction of the photosensitive drum 1is provided with a drum coupling 16 of a triangular prism configuration.A guide portion 19 b of the engaging portion bearing member 19 is guidedby the groove 48 a of a side cover 48 fixed by an unshown screw and soon to the developing unit 4, for movement in the direction crossing withthe axial direction of the developing roller 25. In other words, thedriving side engaging portion 23 is movable in the direction crossingwith the developing unit 4.

FIG. 11 illustrates the structure of the coupling provided in the mainassembly 100A of the apparatus 100. As shown in FIG. 11, the drum drivecoupling 66, which is the first main assembly drive transmission memberfor transmitting the driving force of the main assembly 100A of theapparatus 100 to the photosensitive drum 1, is provided with a hole 66 awhich has the section of substantially triangular shape. The mainassembly development coupling 53, which is the second main assemblydrive transmission member for transmitting the rotational driving force(second rotational driving force) to the developing roller 25 from themain assembly 100A of the apparatus 100, is provided with holes 53 a-53c. The drum drive coupling 66 is urged by a pressing member 77, such asthe compression spring, toward the process cartridge 7. The drum drivecoupling 66 is movable in the axial direction of the photosensitivedrum. When a phase deviation occurs between the drum coupling 16 and thehole 66 a of the drum drive coupling 66 at the time of the mounting, tothe main assembly 100A of the apparatus 100, of the process cartridge 7,the drum drive coupling 66 is pushed and retracted by the drum coupling16. However, the drum coupling 16 and the hole 66 a are brought intoengagement with each other by the drum drive coupling 66 rotating, sothat the rotational driving force is transmitted to the photosensitivedrum 1.

The main assembly development coupling 53 is urged by a pressing member73, such as a compression spring, toward the process cartridge 7 in thedirection parallel with the axial direction of the photosensitive drum1. However, the main assembly development coupling 53 is mounted to themain assembly 100A of the apparatus 100 without play with respect to thedirection crossing with the axial direction. In other words, the mainassembly development coupling 53 is movable only in the axial directionexcept during the rotation for the drive transmission.

When the driving side engaging portion 23 and the main assemblydevelopment coupling 53 engage with each other by the entrance in themain assembly 100A of the apparatus 100 of the process cartridge 7, aphase deviation may occur between the projections 23 c 1 to 23 c 3 andthe holes 53 a-53 c. In this case, the free ends of the projections 23 c1 to 23 c 3 abut at the positions other than the holes 53 a-53 c, andthe main assembly development coupling 53 retracts in the axialdirection against the urging force of the pressed member 73. However,when the main assembly development coupling 53 rotates and the phasesbetween projections 23 c 1-23 c 3 and the holes 53 a-53 c align witheach other, the main assembly development coupling 53 is advanced by theurging force of the pressing member 73. The projections 23 c 1 to 23 c 3and the holes 53 a-53 c are brought into the engagement with each other,so that the centering boss 23 c 4, which is the engaging portionpositioning portion, and the centering hole 53 e, which is transmissionmember positioning portion, are engaged with each other. The axis(rotation axis) of the driving side engaging portion 23 and the mainassembly development coupling 53 are aligned. The projections 23 c 1 to23 c 3 and the holes 53 a-53 c are engaged with each other by the mainassembly development coupling 53 rotating, so that the rotationaldriving force is transmitted to the developing roller 25.

Here, the driving force to the drum drive coupling 66 and to the mainassembly development coupling 53 is supplied from a motor provided inthe main assembly 100A of the apparatus 100. One motor may be providedfor each of the process cartridges, or commonly for a plurality of theprocess cartridges.

(Operation of Oldham Coupling at the Time of DevelopmentSeparation-Contact Operation in Process Cartridge)

Referring to FIG. 12-FIG. 15, the operation of the Oldham coupling inthe process cartridge 7 of this embodiment will be described.

FIG. 12 is a side view which illustrates the state before the processcartridge 7 is mounted to the image forming apparatus 100 main assembly,and FIG. 13 is a longitudinal sectional view thereof.

As shown in FIG. 12, as mentioned above, before the process cartridge 7is mounted to the main assembly 100A of the apparatus, the developingroller 25 and the photosensitive drum 1 are in abutment to each other.An arm portion 18 a of an urging member 18, which is a torsion coilspring provided on the side cover 48, is in abutment to the lockingportion 19 c of the engaging portion bearing member 19. By doing so, thedriving side engaging portion 23 is urged in the direction (thedirection of arrow Q in FIG. 13) crossing with the axial direction ofthe developing roller 25. Therefore, the contact portion 19 d of theengaging portion bearing member 19 is contacted to the contact portion11 c, which is the holding portion provided in the drum-rear bearing 11,and the engaging portion bearing member 19 is positioned. Moreparticularly, the driving side engaging portion 23 is positioned in theconstant position. Here, the contact portion 11 c of the drum-rearbearing 11 is formed by the two surfaces which are in parallel with theaxis of the photosensitive drum 1 and which constitute the shape of a V.The engaging portion bearing member 19 can be retained in parallel withthe axis 1 c of the photosensitive drum 1 by contacting the engagingportion bearing member 19 to this contact portion 11 c. In addition, thedrum-rear bearing 11 is provided integrally with a positioning portion11 b. Therefore, the driving side engaging portion 23 rotatablysupported by the engaging portion bearing member 19 is positioned withhigh precision relative to the rear side plate 83 of the apparatus mainassembly 100A which positions the positioning portion 11 b. Therefore,it is positioned with high precision also relative to the axis 53 d ofthe main assembly development coupling 53 provided in the apparatus mainassembly 100A. The driving side engaging portion 23 of the Oldhamcoupling 20 is rotatably engaged with the engaging portion bearingmember 19. For this reason, although the axis 23 c 5 of the driving sideengaging portion 23 of the Oldham coupling 20 is separated from the axis25 k of the developing roller 25 by the distance d3 in this state, theyare very close to each other. More particularly, the driving sideengaging portion 23 is the positioning position, such that theengagement with the main assembly development coupling 53 is smooth atthe time of the entrance of the process cartridge 7 to the main assembly100A of the apparatus. Although the member which urges the engagingportion bearing member 19 is the urging member 18 in this embodiment,the engaging portion bearing member 19 may be provided with theelastically deformable elastic portion, so that the engaging portionbearing member 19 is contacted to the contact portion 11 c.

A more detailed description will be provided by referring to FIG. 13here. When the driving side engaging portion 23 engages with the mainassembly development coupling 53 and it rotates, the driving sideengaging portion 23 is positioned by the main assembly developmentcoupling 53 as will be described hereinafter. By this, the contactportion 19 b of the engaging portion bearing member 19 is spaced s fromthe drum-rear bearing 11, i.e. the contact portion 11 c. Therefore, whenthe process cartridge 7 enters the main assembly 100A of the apparatus100, the axis 23 c 5 of the driving side engaging portion 23 begins theengagement in the state of being deviated from axis 53 d of the mainassembly development coupling 53 to the photosensitive drum 1 side by apredetermined distance d3. The process cartridge further enters fromthis state, by which the bevelled portion 23 c 6 (FIG. 10) provided inthe centering boss 23 c 4 and 53 f (FIG. 11) of bevelled portionsprovided in the hole 53 e contact with each other, and they engage witheach other, correcting the axial deviation. At this time, the drivingside engaging portion 23 is positioned by the contact portion 11 c withhigh precision relative to the main assembly 100A of the apparatus 100.Therefore, it is positioned with high precision relative to the mainassembly development coupling 53 provided in the apparatus main assembly100A. Therefore, there is no need to substantially upsize the bevelledportion 23 c 6 and the bevelled portion 53 f, and the driving sideengaging portion 23 and the main assembly development coupling 53 can bedownsized. As shown in FIG. 15, when the main assembly developmentcoupling 53 rotates and the phases of the projections 23 c 1 to 23 c 3of the driving side engaging portion 23 and the holes 53 a-53 c of themain assembly development coupling 53 align, the boss 23 c 4 and thehole 53 e engage with each other. By this operation, the rotation axis23 c of the driving side engaging portion 23 and the rotation axis 53 dof the main assembly development coupling 53 align with each other.

FIG. 14 illustrates the state where the process cartridge is mounted tothe main assembly 100A of the apparatus 100. FIG. 15 is a longitudinalsectional view. The driving side engaging portion 23 of the Oldhamcoupling 23 in the process cartridge 7 and the main assembly developmentcoupling 53 of the apparatus main assembly 100A are engaged with eachother in an unshown the main assembly 100A of the apparatus. Moreparticularly, the driving side engaging portion 23 of the Oldhamcoupling 20 is positioned in the main assembly development coupling 53by the engagement with the boss 23 c 4 and the hole 53 e. As shown inFIG. 15, the driving side engaging portion 23 and the main assemblydevelopment coupling 53 are locked with each other with the gap 80between the engaging portion bearing member 19 and the drum-rear bearing11. The axis 25 k of the developing roller, the axis 23 c 5 of thedriving side engaging portion 23, and the axis 53 d of the main assemblydevelopment coupling 53 are substantially aligned. The distances fromthe respective drum axis 1 c are d4.

In the above described embodiment, the rotational driving force isdirectly inputted to the developing roller 25 through the coupling 22from the main assembly development coupling 53 rotated independently ofthe drum drive coupling 66 for inputting the rotational driving force tothe photosensitive drum 1. Therefore, the influence of the rotation ofthe developing roller 25 on the rotational accuracy of thephotosensitive drum 1 is suppressed, and furthermore, the rotationalaccuracy of the developing roller 25 per se is improved, and therefore,the image quality is improved.

In addition, the driving side engaging portion 23 of the Oldham coupling20 is positioned relative to the cartridge 7, and it is movable in thedirection crossing with the axis 25 k of the developing roller 25, andtherefore, the main assembly development coupling 53 and the drivingside engaging portion 23 can engage without using a large guide (savingspace) and so on. Therefore, the process cartridge 7 and the imageforming apparatus 100 can be downsized. In addition, the mountingoperability of the process cartridge 7 to the main assembly 100A of theapparatus 100 is improved.

Embodiment 2

In the first embodiment, the engaging portion bearing member 19 is urgedto the drum-rear bearing 10 which supports the photosensitive drum 1. Asshown in FIG. 16, however, the contact portion 27 f which is the holdingportion contactable to the engaging portion bearing member 19 may beprovided in the cleaning frame 27.

FIG. 16 illustrates the state before the process cartridge 7 is mountedto the main assembly 100A of the apparatus. As has been described withrespect to Embodiment 1, the arm portion 18 a of the urging member 18,which is provided on the side cover 48 and which is a twisted coilspring, contacts the locking portion 19 c of the engaging portionbearing member 19. By this operation, the driving side engaging portion23 is urged in the direction crossing with the axial direction of thedeveloping roller 25. Therefore, the contact portion 19 d of theengaging portion bearing member 19 is contacted to the contact portion27 f provided in the cleaning frame 27, so that the engaging portionbearing member 19 is positioned in place. The contact portion 27 f ofthe cleaning frame 27 is formed by two surfaces which are in parallelwith the axis of the photosensitive drum 1 and which constitute a Vconfiguration. The cleaning frame 27 is provided with the drum-rearbearing 11, and the drum-rear bearing 11 is provided integrally withpositioning portion 11 b. Therefore, the driving side engaging portion23 rotatably supported by the engaging portion bearing member 19 ispositioned with high precision relative to the rotation axis of thephotosensitive drum 1 and the main assembly 100A of the apparatus 100.For this reason, it can be positioned with high precision relative tothe axis 53 d of the main assembly development coupling 53 provided inthe main assembly 100A of the apparatus 100. The other structures arethe same as that of those of the first embodiment, and the effectssimilar to the effects of the first embodiment are provided.

Embodiment 3

Although the Oldham coupling is used as the shaft coupling member in thefirst embodiment, a spring which is the elastic portion may be used asthe intermediary engaging portion 22 of the shaft coupling member 20 asshown in FIG. 17, in the process cartridge, which includes thedeveloping roller, which has a small diameter.

In FIG. 17, the shaft coupling member 20 comprises a driven sideengaging portion 21, an intermediary engaging portion 22, and a drivingside engaging portion 23. The intermediary engaging portion includes aspring 22. The driven side engaging portion 21 is provided with a boss21 a for the engagement of the spring 22. Similarly, the driving sideengaging portion 23 is provided with a boss 23 a which engages with thespring 22. The spring 22 is provided with an arm portion 22 a engagedwith the driven side engaging portion boss 21 a, and an arm portion 22 bengaged with the driving side engaging portion boss 23 a. The shaftportion 23 b of the driving side engaging portion 23 is rotatablyengaged with the hole 19 a of the engaging portion bearing member 19.The driving side engaging portion 23 is provided integrally with theprojections 23 c 1-23 c 4 engaged with the main assembly developmentcoupling 53 which is the second main assembly drive transmission memberof the main assembly 100A of the apparatus. Similarly to embodiment 1,when the driving force of the main assembly 100A of the apparatus 100 istransmitted to the driving side engaging portion 23, the driving forceis transmitted to the arm portion 22 b of the spring 22 from thedevelopment side coupling boss 23 a. The rotational driving forcetransmitted to the spring 22 is transmitted to the boss 21 a of thefollow-engaging portion 21 from the arm portion 22 a of the spring 22.

As shown in FIG. 18, although the spring 22 is used as the intermediaryengaging portion in this embodiment, an elastic rubber 22 of thecylindrical-shape may be used as the elastic portion. The insidecircumference of the elastic rubber 22 is provided with a rib 22 a fortransmitting the driving force by the engagement with the boss 23 a ofthe driving side engaging portion 23 and with the boss 21 a of thedriven side engaging portion 21.

The other structures are the same as that of those of the firstembodiment, and the effects similar to the effects of the firstembodiment are provided.

Embodiment 4

In the first embodiment, the engaging portion bearing member 19 is urgedto the drum-rear bearing 10 which supports the photosensitive drum 1 bythe urging spring 18. As shown in FIG. 19 (a), in this embodiment, thedrum-rear bearing 11 is provided with a hole 11 f which is the holdingportion for retaining driving side engaging portion 23. An innerdiameter of the hole 11 f is large as compared with the outer diameterof the driving side engaging portion 23. More particularly, the drivingside engaging portion 23 is retained for movement in the directioncrossing with the axis of the developing roller 25 relative to the hole11 f. As shown in FIG. 18, in embodiment 1, the driving side engagingportion 23 is positioned through the engaging portion bearing member 19with the deviation relative to the axis 53 d of the main assemblydevelopment coupling 53 in the direction of positioning relative to thedrum-rear bearing 11. In this embodiment, the structure is such that theaxis 23 c 5 of the driving side engaging portion 23 deviates inwhichever direction with respect to the direction crossing with the axisof the developing roller 25. For this reason, also when the processcartridge 7 enters the main assembly 100A of the apparatus, the drivingside engaging portion 23 is smooth in the engagement with the mainassembly development coupling 53. FIG. 19 (b) illustrates the statewhere the driving side engaging portion 23 is positioned by the mainassembly development coupling (unshown). In more detail, the drivingside engaging portion 23 is positioned by the main assembly developmentcoupling (unshown), by which it is in the state of not contacting thehole 11 f.

As shown in FIG. 20, the hole 27 f for retaining the driving sideengaging portion 23 may be provided in the cleaning frame 27.

The other structures are the same as that of those of the firstembodiment, and provide the effects similar to the effects of the firstembodiment.

Other Examples

In the above described embodiment, although the four process cartridgesare used, this number is not inevitable but may be selected suitably, ifnecessary, by one-skilled-in-the-art.

In the embodiments mentioned above, although the image forming apparatusis a type of printer, the present invention is not limited to this. Forexample, it is applicable also to other image forming apparatuses, suchas a copying machine and a facsimile device, and other image formingapparatuses, such as a composite machine thereof. In addition, althoughthe intermediary transfer member is used in the embodiment mentionedabove, the color toner images are superimposedly transferred onto theintermediary transfer member sequentially and the toner images carriedby the intermediary transfer member are transferred onto the transfermaterial all together, the present invention is not limited to thistype. For example, in an alternative structure, the recording materialcarrying member is used and the color toner images are superimposedlytransferred onto the recording material carried by the recordingmaterial carrying member sequentially. The similar effects are providedwhen the present invention is applied to these types of image formingapparatuses.

As has been described hereinbefore, according to the present invention,a large guide for the engagement with the engaging portion and thesecond main assembly drive transmission member is unnecessary.Accordingly, the process cartridge and the electrophotographic imageforming apparatus are downsized. Furthermore, the engaging portion andthe second main assembly drive transmission member of the shaft couplingmember engage with each other smoothly, and therefore, the mountingproperty of the apparatus is improved.

In addition, the rotational accuracy of the developing roller can beimproved, and therefore, the image quality can be improved.

While the invention has been described with reference to the structuresdisclosed herein, it is not confined to the details set forth, and thisapplication is intended to cover such modifications or changes as maycome within the purposes of the improvements or the scope of thefollowing claims.

This application claims priority from Japanese Patent Applications Nos.332838/2006 and 259661/2007 filed Dec. 11, 2006 and Oct. 3, 2007,respectively, which are hereby incorporated by reference.

1-15. (canceled)
 16. A process cartridge detachably mountable to a mainassembly of an electrophotographic image forming apparatus, wherein themain assembly includes a first rotatable main assembly drivetransmission member, and a second rotatable main assembly drivetransmission member, said process cartridge comprising: anelectrophotographic photosensitive drum; a developing roller configuredand positioned to develop an electrostatic latent image formed on saidelectrophotographic photosensitive drum with a developer; a drumcoupling member, provided on one end of a rotational axis of saidelectrophotographic photosensitive drum, configured and positioned toengage the first rotatable main assembly drive transmission member andto transmit a first rotational driving force to said electrophotographicphotosensitive drum; a shaft coupling member, provided on one axial endof said developing roller, configured and positioned to transmit asecond rotational driving force with a deviation permitted between arotational axis of the second rotatable main assembly drive transmissionmember and a rotational axis of said developing roller, with respect toa direction crossing the rotational axis of said developing roller,wherein said shaft coupling member includes an engaging portionconfigured and positioned to engage the second rotatable main assemblydrive transmission member and to receive the second rotational drivingforce, and wherein said engaging portion is movable in the directioncrossing the direction of the rotational axis of said developing roller;and a holding portion configured and positioned to hold said engagingportion such that a rotational axis of said engaging portion is placedin a position deviated from the rotational axis of said developingroller with respect to the crossing direction to engage said engagingportion with the second rotatable main assembly drive transmissionmember.
 17. A process cartridge according to claim 16, wherein saidengaging portion is positioned to contact said holding portion providedon said process cartridge by being urged in the crossing direction. 18.A process cartridge according to claim 16, wherein said holding portionis provided on a drum bearing that rotatably supports saidelectrophotographic photosensitive drum.
 19. A process cartridgeaccording to claim 18, wherein said drum bearing is provided with acartridge positioning portion configured and positioned to position saidprocess cartridge by contacting a main assembly positioning portionprovided in the main assembly of the apparatus.
 20. A process cartridgeaccording to claim 16, wherein said holding portion is provided on aframe of said process cartridge.
 21. A process cartridge according toclaim 20, wherein said frame is provided with a drum bearing having acartridge positioning portion configured and positioned to position saidprocess cartridge by contacting the main assembly positioning portionprovided in the main assembly of the apparatus, said drum bearing beingeffective to rotatably support said electrophotographic photosensitivedrum.
 22. A process cartridge according to claim 17, wherein saidprocess cartridge includes an urging member that urges said engagingportion in the crossing direction.
 23. A process cartridge according toclaim 16, wherein said engaging portion includes an engaging portionpositioning portion configured and positioned to engage the secondrotatable main assembly drive transmission member to be positioned bythe second rotatable main assembly drive transmission member.
 24. Aprocess cartridge according to claim 16, wherein said process cartridgeincludes an engaging portion bearing member which is movable in thecrossing direction relative to said developing roller and whichrotatably supports said engaging portion, and said engaging portion ispositioned to contact said holding portion through said engaging portionbearing member.
 25. A process cartridge according to claim 16, whereinsaid shaft coupling member is an Oldham coupling.
 26. A processcartridge according to claim 16, wherein said shaft coupling memberincludes an elastic portion configured and positioned to permit adeviation between the rotational axis of said engaging portion and therotational axis of said developing roller with respect to the crossingdirection.
 27. An electrophotographic image forming apparatus forforming an image on a recording material, comprising: (i) a rotatablefirst main assembly drive transmission member and a rotatable secondmain assembly drive transmission member; (ii) a process cartridgemounted detachably to the main assembly of said electrophotographicimage forming apparatus, said process cartridge including: anelectrophotographic photosensitive drum; a developing roller configuredand positioned to develop an electrostatic latent image formed on saidelectrophotographic photosensitive drum with a developer; a drumcoupling member, provided on one end of a rotational axis of saidelectrophotographic photosensitive drum, configured and positioned toengage with the rotatable first main assembly drive transmission memberand transmitting a first rotational driving force to saidelectrophotographic photosensitive drum; a shaft coupling member,provided on one end of a rotational axis of said developing roller,configured and positioned to transmit a second rotational driving forcewith a deviation permitted between a rotational axis of said rotatablesecond main assembly drive transmission member and a rotational axis ofsaid developing roller with respect to a direction crossing therotational axis of said developing roller, wherein said shaft couplingmember includes an engaging portion configured and positioned to engagesaid rotatable second main assembly drive transmission member and toreceive the second rotational driving force, and wherein said engagingportion is movable in the direction crossing the direction of therotational axis of said developing roller; and a holding portionconfigured and positioned to hold said engaging portion such that arotational axis of said engaging portion is placed in a positiondeviated from the rotational axis of said developing roller with respectto the crossing direction to engage said engaging portion with saidsecond main assembly drive transmission member; and (iii) feeding meansfor feeding the recording material.
 28. An apparatus according to claim27, further comprising a main assembly positioning portion configuredand positioned to position said process cartridge by engaging a drumbearing having said holding portion to rotatably support saidelectrophotographic photosensitive drum.
 29. An apparatus according toclaim 27, wherein said rotatable second main assembly drive transmissionmember is provided with a hole configured and positioned to transmit thesecond rotational driving force, wherein said hole is engaged with aprojection provided on said engaging portion, and wherein said rotatablesecond main assembly drive transmission member is urged toward saidprocess cartridge by an urging member provided in said main assembly ofsaid apparatus.
 30. An apparatus according to claim 27, wherein the saidrotatable second main assembly drive transmission member includes atransmission member positioning portion engageable with said engagingportion to position said engaging portion.
 31. A process cartridgeaccording to claim 16, further comprising a pressing member configuredand positioned to apply pressure to said developing roller to contactsaid developing roller to said electrophotographic photosensitive drum.32. An apparatus according to claim 27, wherein said process cartridgefurther includes a pressing member configured and positioned to apply apressure to said developing roller to contact said developing roller tosaid electrophotographic photosensitive drum.